ABSTRACT
Cronobacter is implicated in various types of infections involving newborns and infants, including necrotizing enterocolitis (NEC), meningitis, and sepsis. Although the Cronobacter genus comprises a diverse group of gram-negative bacilli (C. sakazakii, C. muytjensii, C. malonaticus, C. turicensis, C. universalis, C. dublinensis, and C. condimenti), C. sakazakii, C. malonaticus, and C. turicensis predominate clinical isolations from infants (1,2). Originally identified as yellow pigmented bacteria, Enterobacter cloacae was subsequently reclassified as C. sakazakii (1). Cronobacter infections are life threatening, with case fatality rates ranging between 40% and 80% (1,3,4). Apart from infections in neonates due to consumption of contaminated infant powdered formula, older and immunocompromised adults may also become infected occasionally. The Centers for Disease Control and Prevention (CDC) have dispatched warnings to public and hospital on the potential outbreaks of Cronobacter infection in neonatal intensive care units (5). Branded as a foodborne pathogen, the opportunistic Cronobacter bacteria are found in a variety of food sources that include dairy-based foods (cheese), dried meats, and rice (6). Soil, livestock facilities, and food preparation units are also sources for Cronobacter. Resistance to heat, dryness, and acidic conditions is a quality of Cronobacter compared to other Enterobacteriaceae family members, thereby enabling its survival in extreme environments (7). Cronobacter also forms biofilms that serve as protective barriers to withstand environmental stresses and escape immune surveillance by the host (8–11).
